Georges Racinet <georges.racinet@octobus.net> [Wed, 03 Jan 2024 18:33:39 +0100] rev 51157
pycompat: fix bytestr(bytes) in Python 3.11
In Python 3.10, the `bytes` type itself does not have a `__bytes__`
attribute, but it does in 3.11. Yet `bytes(bytes)` does not give
the wished output, so we have to add an exceptional case.
The added case in the doctest reproduces the problem with Python 3.11.
Impact: error treatment in expressions such as `repo[b'invalid']` gets
broken.